Indexing device for squaring shear



A ril 6, 1965 J. w. KOOTZ 3,17

- INDEXING DEVICE FOR SQUARING SHEAR Filed Aug. 30, 1962 2 Sheets-Sheet 1 FIG? .3

INVENTORv JAM/M072 YULQM zirroe/v'y A ril 6, 1965 J. w. KOOTZ 3,176,559

INDEXING DEVICE FOR SQUARING SHEAR Filed Aug. 50, 1962 2 Sheets-Sheet 2 Mm? INVENTOR.

JZl/N W 6072 BY LL40 Q Arroen/ey United States Patent This invention relates to work piece guidance devices for fabricating machines and particularly to 1mproved indexing devices for sheet-metal-cuttmg :squarlng shears.

In a conventional sheet-metal-cutting squaring shear a broad vertical ram or blade above the edge of a horizontal workface descends vertically through a flat horizontal stock of sheet metal resting upon and extending over the edge of the horizontal workface. The overhanging metal is cut off at the edge of the supporting workface and falls into a receiving hopper. then rises. An operator or automatic means, advances the remaining stock beneath the ram and beyond the workface edge, a distance determined by an adjustable back gage against which the advancing edge of the stock is made to abut. However, the droop inherent in overhanging sheet metal, unsupported as it is in extending over the edge of the table, unfavorably aifects the dimensional accuracy of the metal ultimately cut away from the stock. Also, unless the back gage is sufficiently large in the vertical direction, the leading edge of the advancing but dooping sheet metal may not abut against the back gage at all.

Thus, it is an object of this invention to provide an improved indexing device for the advancing sheet metal which will prevent the droop inherent in the unsupported length of sheet metal extending over the work edge, but nevertheless allow the metal to fall away once it is cut.

More generally, an object of the invention is to provide an improved workpiece-handling device for a fabricating machine which will guide the leading edge of the workpiece against an indexing member regardlessof extraneous effects.

Another object of the invention is to provide a means to accurately guide the leading edge of the sheet metal advancing between cuts into abutment with the back gage.

Still another object of the invention is to accomplish the above while permitting the cut metal to fall unobstructed into a receiving hopper after each cut.

According to a feature of the invention, the workpiece to be fabricated is advanced with its leading portion against a member defining an inclined plane and constraining the leading portion to abut against an indexing member. According to another feature of the invention coupling means connect the member defining the inclined plane to the operating member, for example the ram in a shear, for withdrawing the inclined-plane member as the workpiece is fabricated. This affords easy removal of the fabricated portion.

According to still another feature of the invention, in a shear, the leading or front edge of the sheet metal stock is advanced against a member defining an inclined plane which descends from the back gage toward the shear. The inclined plane forces the advancing but drooping front edge upwardly until it abuts against the back gage. According to a further feature of the invention, coupling means between the ram and the inclined-plane or -edge member temporarily withdraw the member from under the leading edge while the ram descends, thus permitting the cut metal to fall unobstructed.

These and other features of the invention will be best understood from the following description of preferred The ram embodiments of the invention when considered with the accompanying drawings wherein:

FIG. 1 shows perspectively [a squaring shear having an improved indexing device embodying features of this invention;

FIG. 2 is a sectional view of the shear in FIG. 1;

FIG. 3 is a somewhat schematic detailed view of a portion of the indexing device in FIG. 1;

FIG. 4 is another detailed view of a portion of the indexing device in FIGS. 1 to 3 showing the inclined-plane members of the indexing device in their retracted or downward position;

FIGS. 5 and 6 are perspective and sectional views respectively ofia portion of another indexing device adaptable to the shear in FIG. 1 and embodying features of the invention;

FIG. 7 is a schematic outline of an inclined-plane finger from the embodiment in FIGS. 5 and 6 showing two positions which it may assume relative to the axis of the shaft upon which it is mounted; and

FIG. 8 is a perspective view of an extension member adapted to be secured to the individual inclined-plane members or fingers for increasing the length of the inclined-plane or edge.

The device according to the invention is illustrated [herein in connection with a shear although it will be recognized that it may be utilized otherwise, for example with a brake, or die.

According to FIGS. 1 and 2 a conventional squaring shear rests upon a bed 12 and comprises a table 14 having a horizontal work surface 16 and a pair of end supports 18. The surface 16 is adapted to support a sheet metal worksheet or workpiece 20 which may be slidingly advanced between the end supports 18. Mounted for vertical movement between the supports 18 is a ram assembly consisting of a clamp 22 resiliently carried upon a shearing ram or blade 24 whose vertical position is determined by a foot pedal or an automatic operating device. In its retracted upward position, the ram or blade 24 is held by direct linkage with an actuating crank (cam) coupled to a motor drive (not shown). Pressure applied to the foot pedal, actuates the crank (cam) which by virtue of the direct linkage, forces the ram or blade 24 downwardly. In its downward movement the ram carries with it the clamp 22 which reaches the workpiece 20 first and clamps it securely against the surface 16. A resilient coupling between the ram 24 and clamp 22 permits further downward motion of the ram even while the clamp abuts against workpiece 20. The stroke of the ram 24 continues until it passes across the face of the Worksheet 20 so as to slide against a vertical cutting surface 26 on the table 14. The action shears the workpiece so that the overhanging portion extending beyond the surface 26 is separated from the remainder of the sheet metal stock. After each cut, the foot pedal is released and the crank (cam) returns the ram 24 to its upward retracted position. 7

A pair of horizontally extending bars 28 secured to the ram structure 24 sustain a back gage 34 at the horizontal level of the surface 16 for accurately setting the length of workpiece 20 extending beyond the surface 26. A sleeve block 30 is slidingly secured on each bar 28 and receives in a lower bore a return rod 32 supportingthe L-cross-sectional back gage 34. The back gage 34 extends the entire length of the table between the bars 28; Its position relative to the surface 26 is determined by moving the sleeve blocks 30 upon the bars 28. and locking the sleeve blocks 30 by means of screws, bolts or the like (not shown).

Ordinarily an operator passes the sheet metal workpiece- 20 under the yoke support 18 against the back 3 gage 34 which had been previously set for desired cut-off length. Upon depressing afoot lever or an automatic device, the ram 24 cuts the overhanging sheet material off the advanced workpiece, the clamp 22 having prior to the cut been lowered to secure the workpiece in a comparatively rigid position. Upon retraction of the ram or blade 24 to its initial rest position above the workpiece, by the crank linkage or the like, and return of the clamp 22 to a loosened position, the cut off now-fabricated piece drops to a hopper or bin adjacent to table 14 andthe operator advances the. worksheet stock for the succeeding cut.

If the weight and stiffness of the workpiece material is such that, when the worksheet l6 overhangs the work surface 16 and is clamped against the work surface 16 by the clamp 22, the worksheet droops; an accurately measured cut will be virtually impossible. According to the invention therefore the inclined surfaces upon a plurality of triangular members 36 are adapted to catch the leading edge of the advancing worksh'eet16 and to direct it to a horizontal position on a parallel line with the work surface 16 against the back gage .34 despite its tendency to droop. In FIG. 3 this inclined surface is shown only as part of one triangular member 36 and will be explained in more detail with reference to FIGS. 3 and 4.

In FIG. 3 the triangular member 36 is part of one in a number of assemblies positioned at intervals along the length of the back gage. (See FIG. 1.) These assemblies are all virtually identical and therefore FIG. 3 shows only one of theseassemblies. The triangular member in FIGS. 3 and 4 may be described as a tapered finger, in view of its repetition in the other assemblies, or a pick-up finger secured for movement with a toggle follower 38 about a follower axle 40 between the position in FIG. 3 and FIG. 4. The pick-up finger 36 includes a recess 42 adapted to clear the lower lip of the back gage 34 during movement of the finger. The forward surface 46 of the pick-up finger inclines downwardly toward the work table 14 and comes to a peak 43 in front of the surface 34- at the horizontal level of the work surface 16. Holding the follower axle 40 is a toggle frame 50 having an integral toggle bracket 52 secured by means of screws or bolts, not shown, against the interior surface 54 of the gage 34 away from the direction of the table 14. Also held by the toggle frame Stlis a pivot 56 holding an actuating arm 58 which is biased by means of a coil spring 60 in the clockwise direction against a toggle pin 62 upon the toggle follower 38. The coil spring 60 is secured at one end to a spring brace 64 extending downwardly from the back gage 34 bar to which it is firmly secured. A connecting bar 66 connects together as many of the actuating arms 58 as exist. An eye bolt 68 near each end of the connecting bar holds a tensioned wire cable 69 passing over a horizontal pulley bar 70 mounted upon the support 18 (see FIGS. 1 and 2), and connecting to the ram or blade 24. Alternately the wire cable 69 may connect to the mechanism. operating the ram or blade so long as the tension is applied to the cable to lift the eye 68 in unison with the blade.

To operate the shear according to the invention the desired length of the worksheet to be cut is first determined, and the L-shaped back gage 34 is secured by means of the sleeve block 30 to the desired distance away from the surface 26. An operator places the workpiece 20 upon the work surface 16 and advances the workpiece beyond the edge 26 toward the back gage. When the overhang of the workpiece 20 begins to droop it falls against the forward inclined edge 46 of the pick-up finger 36. As the work-sheet advances further the leading edge thereof is forced upwardly by the pick-up finger 36 and its surface 46 until, when the leading edge abuts against the back gage 34 it rises to the level of the peak 48 on the pick-up finger 36.

The droop thereby is virtually eliminated. The operator then, by depressing a foot pedal or operating a push-button, lowers the ram 24. This first clamps the workpiece 20 into position against the surface 16 by means of the clamp 22 and then lowers further the ram 24 thus separating the overhanging portion of the worksheet 29 beyond the surface 26 from the remainder of the worksheet. The lowering of the clamp 22 and the ram 24 however draws the wire cable 69 downwardly over the pulley bar 76 and lifts the connecting bar 66 alongwith the connecting arms 58 against the tensional force of spring 60. A linkage (not show'n) now effects counter-clockwise motion of the toggle follower 38. Toggle clamps of this type are conventional and available under the trademark De-Sta-Co. There results, through the action of the abovementioned linkage, a counter-clockwise movement of the pick-up finger 36 and'the toggle follower 38 about the follower axle 40. The counter-clockwise movement continues until/the entire finger passes to the left of the surface 44 on the back gage bar 34 as shown in FIG. 4. This permits the cut off workpiece 26 to drop into a hopper extending from the table 14.

Release of the actuating mechanism for theram 24 returns the ram to its upward retracted position thereby releasing the wire cable 69 and permitting the return of spring 66 so as to move the actuating arm 58 clockwise about the pivot 56. This motion of the actuating arm 58 against the toggle pin 62 returns the toggle follower 38, by clockwise movement about the follower axle 4i) and against the force of spring 69, to its initial position. Thus the pick-up finger 36 is returned to the position shown in FIG. 3.

The operator now again advances the work-sheet 2t toward the back gage, it being understood that the clamp 22 is released with the return of the ram 24 to its rest position, and the cycle is repeated. In this manner accurate cuts are possible and means are provided for clearing the cut workpieces away from the work area.

The apparatus according to the invention may be otherwise embodied. For example, utilizing the shear illustrated in FIGS. 1 and 2 the fingers 36 and associated assemblies may be mounted and actuated by means of a commonshaft. Such apparatus, suitable for attachment to the shear of FIGS. 1 and 2 is shown in FIGS. 5 to 7. According to the embodiment of the invention illustrated in FIGS. 5 to 7, bolts not shown, fasten a horizontally extending bearing plate 192 through bolt holes 164, to the rear of back gauge 34 for supporting the indexing device. Bearings 166 located along the plate 102 rotatably support a horizontal shaft 1% parallel to the back gage 34. In this embodiment, the fingers 36 are secured to the shaft 168 at spaced locations by means of integral uprights 169 for movement in respective planes about the axis of shaft 1% toward and away from the shearing ram 24. A torsion spring embracing the shaft 108 forcibly biases the shaft to rotate the fingers (clockwise in FIG. 5) against a stop member (not shown). At this location the fingers 36 assume the rest position shown in FIG. 5, namely one .of. presenting an inclined edge toward an oncoming metal sheet comparable to the finger position in FIG. 2.

An extension arm 112 projecting horizontally away from the ram in the rest position of FIGS. 3, 6 possesses the eye bolt 68 by means of which it is secured to the cable 69. The'cable connects over a pulley, not shown, to the ram 24 and draws the arm 112 upwardly when the ram descends during a cutting stroke. This movement serves to pivot the fingers 36 about the axis of shaft 108 from the rest position R in FIG. 7 to the downward position D in FIG. 7 for releasing the metal sheet cut during the descending stroke of the ram. Upon the ram rising after the cutting stroke, the torsion spring 110 returns the fingers to their horizontal or rest position.

In this manner, the embodiment shown in FIGS. 5 to 7 operate comparable to the embodiment in FIGS. 1, 2, 3. An operator, manually or automatically advances a sheet past the ram and against the inclined edge of the fingers 36 which raise the advancing front end of the sheet to the level of the table. When the operator lowers the ram 'to thereby cut the sheet, the fingers 35 are withdrawn to release the sheet and permit it to fall into a hopper.

In the event that the sheet metal workpiece exhibits excessive flaccidity so that during its advance its leading edge droops below the finger tips and does not engage the inclined edge of the fingers 36, the latter may be provided with extensions 116 as shown in FIGS. 6 and 8. The extensions each possess two holes or recesses 118 and 120 adapted to receive repectively a fastening bolt 12.2 and an alignment pin 124 in each finger 36. The leading edge 126 of the extension 116 is arranged relative to the holes 118, 120 and members 122, 124 so as to afford accurate alignment of edge 26 with the inclined surface 46 of finger 36. Therefore, when necessary particularly droopy material will still be caught as it advances and accurately aligned by the thus-extended fingers.

Preferably for each descent of ram 24, downward pivotal movement or" fingers 36 is delayed at least until the clamp 22 holds the workpiece firmly. This is accomplished by sufiiciently slackening the cables 69.

While particular embodiments of the invention have been described in detail it will be obvious to those skilled in the art that the invention may be otherwise embodied within the scope of the following claims.

I claim:

1. For a squaring shear wherein a fiat horizontal workpiece is intermittently advanced against a back-gage bar to be cut by a shearing tool, an apparatus for minimizing droop in the fiat metal workpiece comprising:

(a) holding means secured to the back-gage bar;

(b) guide means held by holding means and having an inclined surface extending upwardly toward said bar and adapted to meet the advancing edge of the workpiece and guide it upwardly against said bar, whereby the droop inherent in the workpiece is avoided;

(c) pivot means on said bar to permit articulation of said guide means and said inclined surface relative to said bar;

(d) control means responding to the cutting movement of said ram to articulate said guide means about said pivot means and away from the shear When the workpiece is cut, thereby moving the inclined surface of the guide means from under the edge of the workpiece and permitting the workpiece to fall; and

(e) said control means including a lever arm connected to said guide means and extending from said guide means, spring means for biasing said guide means to the position for guiding the workpiece, a stationary cable guide mounted on said shear, and cable means connecting said lever arm to said ram against said cable guide for drawing the lever arm against the force of said spring means in response to the movement of the ram during shearing motion.

2. For a squaring shear wherein a flat metal workpiece is intermittently advanced over a flat horizontal surface to be cut by a shearing ram near the end of the surface, an apparatus for indexing the length of the flat metal workpiece extending beyond the end of the work surface, comprising:

(a) a back gage bar;

(b) holding means for holding the back gage bar at the level of the work surface and at a predetermined distance from the end of the work surface;

(c) a plurality of triangular fingers on the bar at distributed locations therealong, said fingers having inclined surfaces extending angularly downward from said bar toward said shear, said fingers each being adapted to meet with their inclined surfaces the advancing edge of said workpiece as the workpiece droops beyond the end of the work surface and to guide the edge upwardly toward the bar, whereby the droop of the workpiece is corrected;

(d) a pivot assembly articulatingly securing each of said fingers to said bar to permit pivotal movement of said fingers downwardly away from said shear;

(e) control means to hold said fingers in the position for guiding the end of the workpiece upwardly when the ram is inoperative and responding to the cutting movement of the ram to move said finger downwardly after the workpiece is cut, thereby releasing the workpiece; and

(1) said control means including a lever arm connected to said pivot assembly, spring means connected to said lever arm for biasing said arm toward a position where the fingers are in guiding relation to the workpiece, and cable means connecting the lever arm to the ram for drawing the lever arm against the force of the spring means in response to cutting movement of the ram. v

3. For a squaring shear wherein a flat metal workpiece is intermittently advanced over a flat horizontal surface to be cut by a shearing ram near the end of the surface, an apparatus for indexing the length of the flat metal workpiece extending beyond the end of the Work surface, comprising: Y

(a) a back gage bar;

(b) holding means for holding the back gage bar at the level of the work surface and at a predetermined distance'from the end of the work surface;

(c) a plurality of triangular fingers on the bar at distributed locations therealong, said fingers having inclined surfaces extending angularly downward from said bar toward said shear, said fingers each being adapted to meet with their'inc-lined surfaces the advancing edge of said workpiece as the workpiece *droops beyond the end of the work surface and to guide the edge upwardly toward the bar, whereby the droop of the workpiece is corrected;

(d) a pivot assembly articulatingly securing each of said fingers to said bar to permit pivotal movement of said fingers downwardly away from said shear;

(2) said pivot assembly including a lever arm for articulation relative'to said bar for moving said fingers upwardly;

(f) a flange member on said bar for stopping the articulating movement of said fingers in their guiding position;

(g) connecting means in said assembly for constraining said fingers to act in unison;

(h) a spring connected to said assembly and biasing said rod to move said fingers against said flange member;

(1') cable means coupling said ram to said arm for moving said arm against the force of said spring and lowering said fingers as said ram cuts the workpiece, whereby the workpiece is released when cut.

4. For a squaring shear wherein a flat metal workpiece is intermittently advanced over a flat horizontal surface to be cut by a shearing ram near the end of the surface, an apparatus for indexing the length of the flat metal workpiece extending beyond the end of the work surface, comprising:

(a) a back gage bar;

(b) holding means for holding the back gage bar at the level of the work surface and at a predetermined distance from the end of the work surface;

(c) a plurality of triangular fingers on the bar at distributed locations therealong, said fingers having inclined surfaces extending angularly downward from said bar toward said shear, said fingers each being adapted to meet with their inclined surfaces the advancing edge of said workpiece as the workpiece droops beyond the end of the work surface and to guide the edge upwardly toward the bar, whereby the droop of the workpiece is corrected;

(d) a pivot assembly articulatingly securing each of said fingers to said bar to permit pivotal movement of said fingers downwardly away from said shear;

(2) said pivot assembly including levers for articulation relative to said bar for moving said fingers up-,

wardly;

(f) a flange member on said bar for stopping the articulating movement of said fingers in their guiding position;

(g) a connection rod connecting said levers to act in unison;

(h) a spring connected to said rod and biasing said rod to move said fingers against said flange member;

(1') a cable coupling said ram to said rod for moving the fingers against the force of the spring and lowering said fingers as said ram cuts the workpiece, whereby the workpiece is released when cut;

(i) said holding means including a pair of horizontal support poles extending from said shear, a support block slidably mounted on each pole, and shafts carried by said blocks extending toward said shear and supporting said bar on their ends.

5. For a squaring shear wherein a flat metal workpiece (i) a cable coupling said ram to said rod for lowering said fingers as said ram cuts the workpiece, whereby the workpiece is released when cut;

(i) said holding means including a pair of horizontal 5 support poles extending from said shear, a support block slidably mounted on each pole, and shafts carried by said blocks extending toward said shear and supporting said bar on their ends.

(k) said'bar being comprised of an L member having one surface facing said shear.

6. For a fabricating machine wherein a flexible workpiece is intermittently advanced over a work surface for operation thereon, an apparatus for indexing the length of the workpiece extending beyond the end of the work surface, comprising:

(a) a back-gauge bar;

(b) holding means for holding the back-gauge bar in the plane of the work surface and at a predetermined distance from the end of the work surface;

(0) guide means having an inclined surface extending toward said bar and adapted to meet the advancing edge of the workpiece and guide it to the back-gauge bar; and

is intermittently advanced over a flat horizontal surface to be cut by a shearing ram near the end of the surface, an apparatus for indexing the length of the fiat metal workpiece extending beyond the end of the work surface, comprising:

(a) a back gage bar;

(b) holding means for holding the back gage bar at the level of the work surface and at a predetermined distance from the end of the work surface;

(c) a plurality of triangular fingers on the bar atdistributed locations therealong, said fingers having inclined surfaces extending angularly downward from said bar toward said shear, said fingers each being adapted to meet with their inclined surfaces the advancing edge of said workpiece as the workpiece droops beyond the end of the work surface and to guide the edge upwardly toward the bar, whereby the droop of the workpiece is corrected;

(d) a pivot assembly articulatingly securing each of said fingers to said bar to permit pivotal movement of said fingers downwardly away from said shear;

(2) said pivot assembly including levers for articula-' tion relative to said bar for moving said fingers up wardly;

(f) a flange member onsaid bar for stopping the articulating movement of said fingers in their guiding position;

(g) a. connection rod connecting said levers to act in unison;

(h) a spring connected to said rod and biasing said rod to move said fingers against said flange member;

(d) release means responding to the cutting movement of the ram for moving the guide means with the inclined surface from under the workpiece when the workpiece is cut, whereby the cut portion of the workpiece can drop away from the shear; and

(e) said release means including lever means connected with said guide means for moving said guide means, a spring connected to said lever means for biasing said guide means into the guiding position, and cable means connecting said lever means to the ram for 7 drawing the lever means against the force of the spring means in response to cutting movement of the ram, to thereby lower the guide means and release the workpiece.

7. A device as in claim 2 wherein said pivot means include a toggle device.

8. A device as in claim 2 wherein said pivot means include a shaft upon which said triangular fingers are secured.

WILLIAM W. DYER, JR., Primary Examiner. 

1. FOR A SQUARING SHEAR WHEREIN A FLAT HORIZONTAL WORKPIECE IS INTERMITTENTLY ADVANCED AGAINST A BACK-GAGE BAR TO BE CUT BY A SHEARING TOOL, AN APPARATUS FOR MINIMIZING DROOP IN THE FLAT METAL WORKPIECE COMPRISING: (A) HOLDING MEANS SECURED TO THE BACK-GAGE BAR; (B) GUIDE MEANS HELD BY HOLDING MEANS AND HAVING AN INCLINED SURFACE EXTENDING UPWARDLY TOWARD SAID BAR AND ADAPTED TO MEET THE ADVANCING EDGE OF THE WORKPIECE AND GUIDE IT UPWARDLY AGAINST SAID BAR, WHEREBY THE DROOP INHERENT IN THE WORKPIECE IS AVOIDED; (C) PIVOT MEANS ON SAID BAR TO PERMIT ARTICULATION OF SAID GUIDE MEANS AND SAID INCLINED SURFACE RELATIVE TO SAID BAR; (D) CONTROL MEANS RESPONDING TO THE CUTTING MOVEMENT OF SAID RAM TO ARTICULATE SAID GUIDE MEANS ABOUT SAID PIVOT MEANS AND AWAY FROM THE SHEAR WHEN THE 